1. Field of the Invention
The present invention relates to an orthopaedic implant, and, more particularly, to a tibial knee component.
2. Description of the Related Art
A tibial knee component is implanted within a proximal tibia and engages with a femoral component implanted within a distal femur. The tibial knee component typically includes a bearing which is fixed to a tibial tray. The tibial tray may include a stem which is implanted within the intramedullary (IM) canal in the proximal tibia. The bearing may be in the form of a low friction material highly resistant to wear such as ultra high molecular weight polyethylene (UHMWPE) which is fixed to the tibial tray. Articular movement between the femoral component and the bearing surface of the bearing occurs with relatively low friction and wear characteristics.
It is also known to provide a mobile bearing which moves to a limited extent relative to the tibial tray. During deep flexion between the femur and tibia, the bearing rotates to a limited extent about a longitudinal axis associated with a pivot point at the attachment location between the bearing and tibial tray. Although known designs are adequate to allow limited rotation between the bearing and tibial tray, they may be relatively complex and thus expensive to manufacture.
What is needed in the art is a tibial knee component with a mobile bearing which is easier to manufacture and still allows adequate movement between the bearing and tibial tray during deep flexion of the knee joint.